The Utility of Tissue Immunohistochemistry and Viral Culture in Immunocompromised Patients Based on Endoscopic Findings

Abstract

Purpose: Immunosuppressed patients presenting with gastrointestinal signs and symptoms are often assessed for opportunistic infections with endoscopic mucosal biopsy for tissue immunohistochemistry and viral cultures. However, the utility of this practice is unclear. Methods: Using laboratory and pathology databases we retrospectively identified all patients >18 years old undergoing tissue viral cultures or viral immunohistochemistry (IHC) between January 2005 and November 2011. The results of IHC staining, viral culture results, and endoscopic findings were independently reviewed by different physicians who were not aware of the other results. The primary end point was the diagnostic yield of IHC staining and viral cultures in patients with endoscopically normal and abnormal GI mucosa. Results: A total of 154 patients, age 18 to 80, who underwent a total of 209 procedures (102 upper and 107 lower GI endoscopy) were reviewed. 77% of patients had documented use of an immunosuppressive medication at the time of endoscopy. Endoscopic exam showed 62/209(30%) with ulcerations, 97/209(46%) with non-ulcer abnormal mucosa, and 50/209(24%) with normal mucosa. Of all the specimens, 14/209(7%) were positive for viral cultures and 10/209(5%) had positive IHC staining consistent with viral infection. Of the 14 specimens with positive viral cultures, the endoscopic findings included 12 with ulcers, 2 with erosions, and 2 normal findings. Also, 7/14 of these specimens had positive IHC and 6/14 patients had documented positive viral serology prior to endoscopy. The yield of viral cultures in association with endoscopic findings were 12/62(19%) for ulcers, 2/97(2%) for non-ulcer abnormal mucosa and 2/50 (4%) for normal mucosa. Thus, the yield of positive viral culture in non-ulcerated mucosa biopsies was 4/147 (3%), and 2 out of 4 patients had documented positive viral DNA PCR prior to endoscopy. The yield of positive IHC staining in association with endoscopic findings were 9/62(10%) for ulcers, 1/97(1%) for non-ulcer abnormal mucosa, and 0/50 (0%) for normal mucosa. Thus, the yield of positive IHC staining in non-ulcerated mucosa biopsy was 1/147 (0.7%). Although this patient did not have positive viral culture result, the patient had documented positive serology study, prior to endoscopy. Therefore, the additional yield for IHC was zero. Conclusion: Endoscopic biopsies for IHC and viral cultures often yielded positive results in immunocompromised patients with ulcerated mucosa. However, the yield in the setting of non-ulcerated mucosa is very low and not likely to alter patient management.